In recent years, various devices include wireless functions and are capable of connecting to networks, and Internet of Things is now commonly used expression. In order to wirelessly connect a terminal (such as a PC, a smartphone, a tablet, or the like) which serves as a host device and a peripheral device (such as, for example, a keyboard, a mouse, a printer, or the like) to each other, a wireless LAN, Bluetooth (registered trademark), near field communication (NFC), or the like are used in many cases (see, for example, Japanese Laid-open Patent Publication No. 2011-250241, Japanese Laid-open Patent Publication No. 2006-352522, Japanese Laid-open Patent Publication No. 2006-173678, and Japanese Laid-open Patent Publication No. 2001-189689).
In wireless communication, unlike wire communication, there is no physical signal line, and therefore, communication is enabled by adjusting a frequency and time used for communication between a terminal and a peripheral device and causing data to flow therebetween. The state in which this communication is possible is called the “wireless connection state”. For example, when connecting devices through Bluetooth low energy (BLE), which is the latest version of the Bluetooth standard, whether or not there is data that is to be transmitted and received, synchronous communication is performed at predetermined intervals while changing the frequency used by the devices (the connection is called synchronous connection).
Setting of synchronization may be determined on a master (terminal) side, but may not be determined on a slave (peripheral device) side. Setting parameters include three types, that is, a communication interval (connection interval), the number of times non-communication on the slave side is allowed (connection slave latency), and a timeout time that is considered to be disconnection (connection supervision timeout). Data transmission and reception may be performed only at a timing of synchronization, and therefore, communication speed (throughput) and power consumption of a device are caused to vary by adjusting the parameters. As the communication interval (synchronization interval) is increased, the power consumption is reduced, but a communication delay tends to occur (power saving priority). On the other hand, as the communication interval is reduced, a communication delay is reduced, but the power consumption is increased (communication speed priority). In order not to increase the complexity of setting, in many cases, only priority designation may be performed via an application (app). For example, in a terminal in which an Android (registered trademark) OS is installed, an app may be in one of the following three modes, that is, High: communication speed priority is set such that a communication interval is set to be short, Low: power saving priority is set such that a communication interval is set to be long, and Balanced: communication speed and power consumption are intermediate such that a communication interval is set to be intermediate.
FIG. 1 is a diagram illustrating an example of a terminal and a BLE device according to a related technology, and in FIG. 1, a case where the terminal is connected to the BLE device through a BLE framework (FW) of an execution environment via BLE communication sections of apps #1 and #2 of the terminal is illustrated.
FIG. 2A and FIG. 2B are diagrams each illustrating an example of a communication interval mode and data transmission, FIG. 2A illustrates an example of data transmission and reception in which the mode is set to “High”, and FIG. 2B illustrates an example of data transmission and reception in which the mode is set to “Low”. When the mode is set to “High”, a communication interval is short (namely a short communication interval is applied) and it takes only a short time to perform data transmission and reception, but, even when there is no data that is to be transmitted and received, communication to identify a communication partner occurs in every communication interval, and the power consumption is increased. Also, when the mode is set to “Low”, a communication interval is long (namely a long communication interval is applied), and therefore, it takes a long time to perform data transmission and reception, but communication to identify a communication partner occurs less frequently, and therefore, the power consumption is reduced.